1. Field of the Invention
The present invention relates generally to lawn and garden implements and, more particularly, to a wire guard assembly for a vegetation cutter.
2. Description of the Related Art
Vegetation cutters have long been used to trim vegetation inaccessible to lawn mowers. One type of vegetation cutter is known as a string trimmer, in which one or more flexible flails, typically made of nylon or an extruded plastic, extend outwardly from a cutting head into a cutting plane. A motive power source, typically either an electric motor or a small gasoline engine, rotates the cutting head. While initially used for trimming grass and weeds around trees, shrubs, fences, and the like, string trimmers are now being used for edging of sidewalks and curbs. By adapting the string trimmer to operate as both a grass and weed trimmer and an edger, the need for a conventional rollable rotating blade edger is eliminated and a person can trim around trees and shrubs and edge sidewalks without having to change equipment between operations.
A practical problem in cutting grass and weeds is the damage that occurs when the rotating flexible flails come into contact with objects that the flails were not intended to trim. When this occurs, the flails must be replaced. Additionally, the rotating flails can cause damage to small trees by wearing away the bark of the tree and the leaving the tree trunk exposed and unprotected. Therefore, string trimmers require a guard that will allow the rotating flails to get close enough to do an effective job on grass and weeds, but not so close as to damage a permanent structure or the string trimmer itself.
Another practical problem arises when the string trimmer is used for edging around sidewalks and curbs. Because the flails are rotating at a high speed, the operator has difficulty seeing the planar cutting circle created by the rotating flails. Because of this inability, it is desirable for the guard described above to act also as an edging guide, which allows the rotating flails to cut a uniform edge along a sidewalk or a curb without coming into contact with the sidewalk or the curb.
Various devices that function as both a guard and an edging guide have been proposed for attachment to string trimmers. Many of these devices attach to the string trimmer proximate the cutting head and extend out to or slightly beyond the cutting circle defined by the rotating flails. Further, each of these devices requires attachment components for mounting the device to the string trimmer. These components are in addition to components required for attaching other devices, such as a debris shield, to the trimmer. Examples of devices used as guards and edging guides are shown in U.S. Pat. Nos. 5,107,665; 5,060,383; 4,894,916; and 4,756,084. By requiring a separate set of attachment components, these designs increase the complexity of manufacturing and assembling the string trimmers.